Displacement issues

[jangwee]

Hey guys,

Having a strange issue with displacement on some simple characters I'm rendering.
Looks like the bottom of character mesh goes invisible with displacement applied.
Checked UVs are ok (not flipped), no seams at problem area on mesh.

Not sure what's going on here.
Any ideas.
Don't want to go back to MentalRay just because of this little problem. It's so slow and frustrating whenever I have to go back to using it.


screenshots attached - MentalRay vs Octane displacement.
(can't show full characters for privacy reasons)

[limeforce]

Totally feel your pain re: Mental Ray being super frustrating & slow! Not sure what's going on there though. Wild guess: could it have something to do with the value range of the displacement map? E.g. Mental Ray interpreting it as [0..1] and Octane as [-0.5..0.5]. Why do the mouths look different, is that related?

[jangwee]

I've played around with the displacement values and offset to get it to match the old mental renders as closely as possible but that didn't change the problem at bottom of characters mesh. Had to go 16bit texture for correct displacement as 32 bit not working properly.

The mouth in previous screengrabs just don't have octane materials yet so rendering with default grey.